Will Shuttles' End Leave Science Landlocked?

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The payload on the final space shuttle trip to the International
Space Station is expected to include containers of plant seeds.
The seeds aboard the shuttle Atlantis, which is scheduled to
launch Friday (July 8), may help scientists understand how plants
respond to the minuscule gravity of low Earth orbit. Research
like this may lead to the development of bio-support systems for
astronauts on long voyages and even help improve agriculture here
on Earth.

The plants
will grow for a week before the crew aboard the space station
freezes them. The leader of the study, Imara Perera, and her team
will examine the tiny plants once they are returned to Earth.

But there’s a hitch in the plan: The plants don’t have a ride
home. With the shuttle program ending, Perera’s plants must
secure space on a commercial flight, and none has begun running
up to the space station yet.

“Of course we are anxious and we would like to get them back as
soon as possible, but we do also want them to come back safely
and intact,” Perera, a research assistant professor of plant
biology at North Carolina State University, told LiveScience.

The gap

Thirty years after the first space shuttle launch, of Columbia,
NASA is ending the space shuttle program with no immediate
replacement for the low-orbiting shuttles, as it focuses
on manned voyages farther afield, like the moon and Mars. At
least in the short term, the gap left by the shuttles will be
filled by a hodgepodge of commercial flights and other nations’
craft, such as the Russian Soyuz and Progess.

This transition has created some uncertainty among American
scientists, who have depended on shuttle flights to ferry or
conduct their experiments. While some anticipate upcoming delays
or limitations on research, Tara Ruttley, NASA's associated
program scientist for the International Space Station, offers
reassuring words.

"Our office feels really comfortable from a research
perspective," Ruttley said. "If you have an investigation you
want to do on the space station, we will get you there."

From shuttle to station

The shuttle program allowed researchers to make significant
progress unraveling how gravity, or the near-absence of it,
affects living systems, according to Kenneth Souza, a longtime
space biologist and senior scientist for Dynamac Corp. assigned
to NASA's Ames Research Center.

The crew members on the shuttle did the work of scientists on the
ground, taking a blood sample or a snip of a plant at a
particular time to see what was happening. This type of
experiment wasn't possible using the earlier, unmanned
satellites, Souza said.

Shuttle missions lasted at most a couple of weeks, putting a hard
time limit on any experiment. Meanwhile, experiments on the space
station, part of which has been designated a U.S. national
laboratory, can stretch out for months or longer, allowing
scientists to look at longer-term effects of exposure to
microgravity or low-dose radiation. [ Inside
and Out: The International Space Station ]

"It is an order of magnitude better for research," said Chris
Brown, director of North Carolina Space Grant and a professor of
plant biology at North Carolina State University. "It is as if
you were building a new house but it took you several too many
years to build the house; while the trucks were driving in with
supplies and dry wall, you were also living in the truck and
cooking in the truck. You could say the truck was very useful,
but now we have the house and you would rather do the work and
live in the house."

The catch

Danny Riley, a professor of cell biology, neurobiology and
anatomy at the Medical College of Wisconsin in Milwaukee, has
studied muscle wasting in rats
and astronauts during spaceflight and recovery on Earth. The
space station provides an important platform for research into
muscle atrophy because experiments can continue over long
periods, mimicking the extended space travel necessary for, say,
a journey to Mars.

Research so far has managed to reduce muscle atrophy, but not
enough, according to Riley, who from his earthly lab is currently
working on the effects of microgravity on posture.

"It is very frustrating because in this interim period of time we
know what experiments should be done, but we can't get there to
do them," ? or they can be done in only limited amounts, he said.

In order to return the American investment in the station to our
economy, we need to use it and reap the benefits, Riley said. "I
don't like being dependent on Russian or Chinese or European
space agencies for access to the space station. I think then we
are second-class citizens."

Atlantis' payload also is slated to include microbes for an
experiment, to be conducted on board. Scientists wish to examine
how microgravity affects the communities of micro-organisms that
form on surfaces, called biofilms — "the stuff you have on your
teeth in the morning, that kind of thing," said researcher
Cynthia Collins, an assistant professor of chemical and
biological engineering at Rensselaer Polytechnic Institute.

Getting the microbes into space and getting them back is, at
least currently, crucial for experiments like this one, but the
end of the shuttle program won't cut off this line of research.
"It's more something we just deal with at this point,"
Collins said. "We are really just excited to have this
opportunity." Her lab in New York is set up to create a
reasonable, but not perfect, match for microgravity.

"We are kind of waiting to see and keeping our fingers crossed
that the commercial ventures will stay on track and are able to
take large packages up in the next few years, and that we will
have the opportunity to send our things up," she told
LiveScience.

The transition is unlikely to affect American scientists'
willingness or ability to do basic research in space over the
next couple of years, according to Souza.

"American scientists have been working with limited access to
space since the beginning of the space program," he said.

Certain research, however, has a particularly uncertain future
without the shuttle. Researchers have studied the ionosphere —
part of the upper atmosphere that contains charged particles
— by observing the effects of exhaust from the shuttles' powerful
Orbital Maneuvering System engines.

The shuttle pilot can precisely control the direction and
duration of the firing of these engines, a feature important to
this research, according to Philip Erickson, an atmospheric
scientist at Massachusetts Institute of Technology's Haystack
Observatory.

"The results [from the Shuttle Ionospheric Modification with
Pulsed Localized Exhaust] so far have pointed to some
possibilities for understanding the ionosphere better, but with
time running out, we just don’t have the capability to make the
follow-up measurements we need to fully understand the results,"
Erickson wrote in an email. It's conceivable these observations
could be conducted with cooperation from a commercial company,
but Erickson said he is not hopeful for this option.

In the meantime NASA has awarded contracts to two companies to
carry cargo to the space station. Orbital Sciences Corporation,
of Dulles, Va., is developing the Taurus II rocket to carry its
Cygnus spacecraft, and Space Exploration Technologies (SpaceX)
from El Segundo, Calif., is developing the Falcon 9 rocket and
Dragon space craft.

SpaceX is waiting for NASA clearance to fly a cargo-resupply
mission to the station late this year, according to spokeswoman
Kirstin Grantham. Orbital Sciences, meanwhile, is on track to
launch its first demonstration flight, also carrying cargo to the
space station early in 2012, according to Carl Walz, Orbital
Sciences' deputy program manager for Cygnus.

NASA has also made arrangements for space on the automated
European, Russian and Japanese cargo flights, and on the Russian
Soyuz vehicle, which has life support.

The shuttles' large cargo space was devoted to carrying up large
pieces of the space station during construction and to equip it.
The commercial and international flights won't need to carry any
of this massive cargo, opening up more space for experiments, at
least on the way up, Ruttley said.

Getting back down is another matter. Of all of the vehicles
traveling to the station in the near future, only the Cygnus and
the Russian Soyuz are capable of returning. The others drop
off their cargo and then burn up in the atmosphere. NASA has
secured limited space on the Soyuz, for sensitive samples such as
blood and saliva, Ruttley said.

There are also plans to improve the station's capacity to analyze
samples on site rather than return them to Earth, according to
Ruttley.

Cynthia Martin-Brennan, executive director of the American
Society for Gravitational and Space Biology, see opportunity in
this transition.

"I think for all of us it's all about having frequent access to
space and being less expensive, because you've got competitors,
and hopefully, multiple vehicles going to the station, we hope
to see a little bit of pricing going on," Martin-Brennan said.
"The shuttle was such a complicated vehicle. It takes a while
to get it to go up, so we are hoping to see more access to
space."